   IEquiv
   (-equiv [coll other] (equiv-sequential coll other))
 
+  IHash
+  (-hash [coll] (hash-coll coll))
+
   ISeqable
   (-seq [coll] nil)
 

  goog.global.Number (-hash [o] o))

(defn hash [o]
  (when o (-hash o)))

(defn- scan-array [incr k array]
  (let [len (.length array)]


  IEquiv
  (-equiv [coll other] (equiv-map coll other))

  IHash
  (-hash [coll] (hash-coll coll))

  ISeqable
  (-seq [coll]
